Effects of higher-order dispersion on pulse splitting in the normal dispersion regime

By solving numerically the extended nonlinear Schrödinger equation we investigate the influence of higher-order dispersion effects on the propagation of optical pulses in the normal dispersion regime in a highly nonlinear fiber. Already a small amount of third-order dispersion can lead to a pulse-breakup above a certain pulse power. The splitting is followed by an expansion of the spectrum towards longer wavelengths without any impact of Raman scattering. The transfer of energy to longer wavelengths strongly depends on the dispersion profile of the fiber.     

The nonlinear refraction and absorption dependence on the thermal effect for 4 ns pulse duration in binuclear Zn(II) phthalocyanine solution

The influence of thermal effect on the third-order nonlinear optical properties of binuclear Zn(II) phthalocyanine in chloroform solution was studied. The nonlinear refraction and absorption of the sample was measured by using Z-scan technique with 4 ns laser pulses at 532 nm wavelength. The opposite signs of the effective nonlinear refraction index were observed by changing the focal length of focusing lens from 10 cm to 20 cm in the experimental setup. Changing the focusing lens increased the beam waist radius from 7 μm to 20 μm. The nonlinear absorption coefficient was reduced about 200 times based on changing the fluence or beam waist radius. The drastic changes in the third-order nonlinear optical parameters were attributed to thermal effect. To investigate the role of thermal effects even further the effective nonlinear refraction and absorption coefficients were studied by using different repetition rates, input powers and concentrations.     

Single-ion conductivity enhancement for the composite polymer electrolytes based on Li(PVAOB)/PPEGMA for lithium-ion batteries

In the present work, a series of single-ion conducting composite polymer electrolytes based on lithium polyvinyl alcohol oxalate borate (Li(PVAOB)) and poly(polyethylene glycol methacrylate) (PPEGMA) were produced. PEGMA was polymerized into PPEGMA, and the Li(PVAOB) was prepared from poly (vinyl alcohol) (PVA), oxalic acid, and boric acid. Li(PVAOB) was blended with PPEGMA at different stoichiometric ratios to obtain a single-ion conducting system. All the electrolytes were characterized by Fourier transformation infrared spectroscopy (FT-IR), thermogravimetry analysis (TGA), differential scanning calorimeter (DSC), and scanning electron microscopy (SEM) techniques. These results verified the interaction between host and guest polymers, sufficient thermal stability within the measured conductivity domain, and the homogeneity of the composite electrolytes. The effect of PPEGMA onto the ionic conductivity was investigated using impedance spectroscopy. The Li(PVAOB)-60PPEGMA is the optimum content, and this sample has a maximum ionic conductivity of 3 × 10^?4 S/cm at 100 °C which is approximately five orders of magnitude higher than neat Li(PVAOB). Activation energy (E _a ) of ionic transport decreased from 11.9 to 0.27 kJ/mol, suggesting a much faster ionic mobility for higher PPEGMA-containing samples.     

A new approach to solar flare prediction

Frontiers of Physics - Graphene oxide (GO), the functionalized graphene with oxygenated groups (mainly epoxy and hydroxyl), has attracted resurgent interests in the past decade owing to its large...